1. Field of the Invention
The present invention relates generally to a device for transporting flat products, and particularly to a device for transporting a flat product including a transport cylinder and a stripper belt following a continuous path that passes between the product and an axis of rotation of the transport cylinder and does not circumscribe the axis of rotation.
2. Background Information
In many applications such as printing, copying, and paper handling, it is desired to transport printed paper signatures or other flat products through various devices to accomplish the required processes. Examples of devices that transport such flat products include folders, bindery equipment, printing presses, photocopiers and the like. In some of these devices, a rotating transport cylinder is used to guide the flat product from one location to another. Typically, the transport cylinder grips a flat product in one location, and releases the flat product in a second location. In order to ensure the proper release of the flat product at the desired location, one or more continuous stripper belts may be employed. A stripper roller having an axis of rotation parallel to a rotational axis of the transport cylinder may be disposed adjacent to the transport cylinder in an area downstream of the desired location at which the flat product is to be released from the transport cylinder. Typically, such stripper belts each follow a respective continuous path that circumscribes both the transport cylinder and the stripper roller, so as to pass between the transport cylinder and the flat product being guided by the transport cylinder. Circumferential grooves may be provided in the transport cylinder and/or the stripper roller to help guide keep the stripper along the respective desired continuous paths. U.S. Pat. No. 6,283,905 describes an example of a device including a stripper belt that circumscribes a transport cylinder. (See FIG. 8).
Such devices for transporting flat products are capable of stripping flat products from the transport cylinder accurately and reliably at the desired release location, minimizing instances of incomplete stripping that can lead to jamming of the flat products. Over time, however, these stripper belts are subject to wear and eventual breakage. Because of the continuous path of the stripper belts circumscribe both the transport cylinder and the stripper roller, replacement of worn or broken belts is a time consuming and difficult task.
Pre-spliced continuous stripper belts cannot be used as replacement belts unless the transport cylinder and stripper roller are first disassembled. Instead, the replacement stripper belts, in the form of long strips must first be wrapped around the transport cylinder and roller in the proper position and then spliced to form a continuous belt. The splicing must be performed accurately to provide the proper tensioning of the belt and to minimize unwanted additional thickness of the belt in the area of the splice. Performing the wrapping and splicing operation is time consuming, difficult to perform within the confines of the device, and subject to error, for example, in the form of improper tensioning of the resulting belt, undesired “lump” in the area of the splice, or a weak splice. During the entire time required for performing this difficult splicing operation, the transporting device must cease operation, thus making the operation potentially very costly.
U.S. Pat. No. 5,688,219 describes a device for transporting flat products in the form of a folding apparatus or folder. Groups of guiding tapes are used to provide positive control of the flat products between a pair of cutting cylinders and a copy guiding cylinder. These guiding tapes are disposed to guide flat products, where the flat products are entrapped between the guiding tapes and the cylinder. One group of guiding tapes follows a continuous path that does not circumscribe the transport cylinder. However, the '219 patent does not describe the use of stripper belts disposed between the flat products and the cylinder.